In a press release, Picard claims UBS actively assisted the Madoff Ponzi scheme by sponsoring and administrating Luxalpha SICAV and Groupement Financier, two feeder funds.

FORBES: Madoff Trustee Sues UBS For $2 billion

Lawyers for Mr. Wilpon and his associates acknowledged in a court filing late Monday that the December lawsuit by Mr. Picard had accused them of overlooking signs that Mr. Madoff was running a Ponzi scheme.

WSJ: Baseball's Mets, Ensnared in Madoff Scheme, Hope to Sell Off Piece by June

As part of the complaint, Picard also sued the widow of the first known suicide victim connected to the Madoff Ponzi scheme.

FORBES: Madoff Trustee Sues UBS For $2 billion

With so-called clawback suits, Picard has also started to sue Madoff victims who took out more from the Madoff Ponzi scheme than they put in.

FORBES: Madoff Trustee Sues JPMorgan Chase For $6.4 billion

Picard would have to essentially prove that Wilpon and Katz knew that Madoff was running a ponzi scheme, a very tough task.

FORBES: Judge Tosses Most of Suit Against Wilpons

The four-page decision by U.S. District Judge Jed Rakoff in New York is a blow to the Mets owners, Saul Katz and Fred Wilpon, who have been in a prolonged legal battle for more than a year with Irving Picard, the court-appointed bankruptcy trustee seeking to find money for victims of Mr. Madoff's Ponzi scheme.

WSJ: Mets Owners Must Return Madoff Profits, Face Trial